CN107074830B

CN107074830B - Difluorobithiophene-based D-A polymers for photovoltaic applications

Info

Publication number: CN107074830B
Application number: CN201580055343.0A
Authority: CN
Inventors: 颜河; 李正珂
Original assignee: Hong Kong University of Science and Technology HKUST
Current assignee: Hong Kong University of Science and Technology HKUST
Priority date: 2014-10-22
Filing date: 2015-10-22
Publication date: 2021-01-22
Anticipated expiration: 2035-10-22
Also published as: EP3209659A4; EP3209659A1; BR112017008384A2; US20170301862A1; CN107074830A; KR20170086511A; US10263190B2; JP2017534621A; WO2016062258A1

Abstract

An organic compound, a D-a conjugated polymer, a formulation and a film, wherein the peak of the optical absorption spectrum of a solution of the D-a conjugated polymer exhibits a red shift of at least 100 nanometers when the solution of the D-a conjugated polymer is cooled from 140 ℃ to room temperature.

Description

Difluorobithiophene-based D-A polymers for photovoltaic applications

RELATED APPLICATIONS

This patent application claims priority to U.S. provisional patent application No.62/122,479, filed by the present inventor on 22/10/2014, which is incorporated herein by reference in its entirety.

Technical Field

This patent mainly relates to: novel organic compounds, D-A conjugated polymers; a preparation method thereof and an intermediate product used in the preparation process; the use of formulations containing such polymers as semiconductors in Organic Electronic (OE) devices, especially in Organic Photovoltaic (OPV) devices and Organic Field Effect Transistor (OFET) devices; and OE devices and OPV devices made from these formulations.

Background

In recent years, there has been an increasing interest in the use of organic semiconducting materials (including conjugated polymers) in various electronic fields.

Organic photovoltaic materials (OPVs) are even more a non-negligible part of the field of organic semiconductors. In the field of photovoltaics, the advantages of organic semiconducting materials (OSCs) are mainly reflected in the fact that they can be produced using solution processing techniques such as spin coating or printing. The solution processing has the advantage over the evaporation techniques used for the manufacture of inorganic thin film devices that it can be mass produced at low production costs. OPV batteries have hitherto been composed of mixed films of conjugated polymers and fullerene derivatives. The current breakthrough in single layer OPV efficiency (Yu et al, nat. photonics 2014,8,716, efficiency: -8% -9%) is mainly based on optimization of narrow bandgap polymers (defined as polymers with an initial absorption wavelength above 750 nm and a bandwidth below 1.65 eV). (for example, low performance OPV polymer materials such as P3HT with band gaps as high as-1.9 eV are not considered).

Currently, polymers commonly used in the field of PSC are composed of electron donating (donor or D) comonomer units and electron accepting (acceptor or a) comonomer units. The use of this D-A alternating copolymer approach allows for a fast and efficient process to obtain polymers with smaller optical bandgaps because the HOMO of the polymer is determined primarily by the donor block and the LUMO is determined primarily by the acceptor block. A currently widely accepted design model is proposed by Brabec et al, in which the HOMO and LUMO energy levels of the macromolecules are the fundamental conditions for designing high performance polymer solar cells due to their open circuit voltage (V)_oc) Is determined by the difference between the HOMO energy level of the polymer and the LUMO energy level of the fullerene derivative. The LUMO energy level is relatively more important because the LUMO of polymers and fullerenes should be small enough to convert V to V_ocThe loss of (a) is minimized. By modifying the acceptor block with an electron donating group or an electron withdrawing group, the LUMO level of the D-a polymer can be effectively adjusted, as can the HOMO level of the donor block.

In the field of conjugated polymers for PSCs, fluorination methods are effective means for modifying conjugated polymers to adjust HOMO and LUMO energy levels. In known reports, the acceptor building block part of the D-A conjugated polymer is fluorinated to effectively adjust the energy level of the conjugated polymer, accompanied by other beneficial changes such as strengthening the polymer stackVolume characteristics and crystallinity. As in 2013, You et al (j.am. chem. soc.2013, 135, 1806) studied the difluorination of a benzotriazole unit, and experimental results demonstrated that difluorination lowers the HOMO level (thereby increasing the V of a solar cell)_oc) And enhances the packing of the polymer in the solid phase. However, there are few reports of improved PSC device performance by fluorination of the donor portion of D-A conjugated polymers. In the past failure cases, it was believed that perfluorinated polymer backbones (both donor and acceptor blocks having fluorine) would degrade PSC performance, leading to very strong self-assembly characteristics and fluorine-phobic action of the polymer.

Disclosure of Invention

This patent relates to organic compounds having the following structural formula:

the present patent also relates to D-a conjugated polymers comprising one or more repeat units having the formula:

the present patent also provides a D-a conjugated polymer comprising at least one or more repeat units having the formula:

wherein Ar is an aromatic group independently selected from the group consisting of:

each R is independently selected from linear, branched or cyclic alkyl having 2 to 40 carbon atoms, wherein one or more nonadjacent carbon atoms may optionally be replaced by-O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -CR⁰＝CR⁰⁰-, or-C.ident.C-substitution; and wherein one or more H atoms may be replaced by F, Cl, Br, I or CN, or represent aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl, or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted with one or more non-aromatic groups; wherein R is⁰And R⁰⁰Independently a linear, branched or cyclic alkyl group. In some embodiments, the Ar group contains two aromatic rings.

The patent also relates to D-A conjugated polymers having an average molecular weight of between 20,000g/mol and 40,000 g/mol.

The absorption spectrum peaks of the D-a conjugated polymers of this patent show a very strong red shift (greater than 100 nm) during cooling from high temperature (e.g., 140 ℃) to room temperature, which is surprisingly associated with the excellent polymer/fullerene morphology formed by the D-a conjugated polymers.

The patent also relates to the use of a formulation comprising an organic solvent, a fullerene and a D-a conjugated polymer as described above and below.

The patent also relates to the use of the formulations as described above and below as coatings or printing inks, especially for the production of OE devices or rigid or flexible Organic Photovoltaic (OPV) cells and devices.

The patent also relates to OE devices prepared from the formulations described above and below. OE devices contemplated in this regard include, but are not limited to, Organic Field Effect Transistors (OFETs), Integrated Circuits (ICs), Thin Film Transistors (TFTs), Radio Frequency Identification (RFID) tags, Organic Light Emitting Diodes (OLEDs), organic light emitting transistors (OLEDs), electroluminescent displays, Organic Photovoltaic (OPV) cells, Organic Solar Cells (OSCs), flexible OPVs and O-SCs, organic laser diodes (O-lasers), organic integrated circuits (O-ICs), lighting devices, sensor devices, electrode materials, photoconductors, photodetectors, electrophotographic recording devices, capacitors, charge injection layers, schottky diodes, planarization layers, antistatic films, conductive substrates, conductive patterns, photoconductors, electrophotographic devices, organic memory devices, biosensors, and biochips.

The present patent also provides a film comprising a D-a conjugated polymer as described above and below and a fullerene.

The D-a conjugated polymer having the structure as described above has excellent solubility in an organic solvent and processability, and thus is particularly suitable for mass production using a solution processing method. Meanwhile, the polymer shows narrower bandwidth, higher mobility and higher external quantum efficiency in the BHJ solar cell, and is compatible with dozens of fullerenes, so that the polymer shows high photoelectric conversion efficiency in organic electronic OE devices, especially OPV devices, and has excellent application prospects.

The compounds, formulations, production methods and devices referred to in this patent show a great improvement in the efficiency of OE devices and their manufacture. Unexpectedly, OE electrical devices could produce significant improvements in performance, lifetime, and efficiency if the formulations of this patent could be used. In addition, the formulations of the present invention provide good film forming properties. In particular, the uniformity and quality of the film are improved. Furthermore, the present patent may provide a better production of OE devices, in particular OPV devices, by means of solution printing.

Drawings

It should be understood that the drawings described above and below are for illustration purposes only. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. The drawings are not intended to limit the scope of the present invention in any way.

FIG. 1 shows a UV-Vis spectrum of a polymer in a film according to one embodiment of this patent.

FIGS. 2a-d show cyclic voltammograms of a polymer in a 0.1M solution of (N-Bu)4N + PF6 acetonitrile according to the measurement method taught by this patent.

Figure 3 lists AFM surface topography maps and phase diagrams for hybrid films containing different fullerenes and polymers as taught in this patent.

Detailed Description

Definition of

In the present application, when a composition is described as having, including, or containing a particular component, or when a method is described as having, including, or containing a particular process step, then the composition of the present teachings can also consist essentially of, or consist of, the recited component, and the method of the present teachings can also consist essentially of, or consist of, the recited process step.

In the present application, when an element or component is described as being included in and/or selected from a list of listed elements or components, it is to be understood that the element or component can be any one of the listed elements or components, or the element or component can also be selected from a group consisting of two or more of the listed elements or components. Moreover, it should be understood that the elements and/or features of the compositions, devices, or methods described herein may be combined in various ways, whether explicitly described herein or not, without departing from the spirit and scope of the present teachings.

Unless specifically stated otherwise, in this patent, "include", "have", and the like are to be understood as open-ended and non-limiting.

The use of the singular herein includes the plural (and vice versa) unless explicitly stated otherwise. Furthermore, when the term "about" is used before a numerical value, the present teachings also include the specific numerical value itself, unless specifically stated otherwise. As used herein, unless otherwise specified or inferred, the term "about" means within ± 10% of the nominal value.

It should be understood that the order of steps or order of performing certain actions is immaterial so long as the present teachings remain operable. Further, two or more steps or actions may be performed simultaneously.

As used herein, a "p-type semiconductor material" or "A donor "material refers to a semiconductor material, such as an organic semiconductor material, having holes as the predominant current or charge carrier. In some embodiments, more than about 10 a may be provided when a p-type semiconductor material is deposited on a substrate^-5Hole mobility in cm/Vs. In the case of field effect devices, the p-type semiconductor may also exhibit a current on/off ratio of greater than about 10.

As used herein, an "n-type semiconductor material" or "acceptor" material refers to a semiconductor material, such as an organic semiconductor material, having electrons as the predominant current or charge carrier. In some embodiments, the n-type semiconductor material may provide more than about 10 when deposited on the substrate^-5Electron mobility in cm/Vs. In the case of field effect devices, n-type semiconductors may also exhibit a current on/off ratio of greater than about 10.

As used herein, "mobility" refers to a measure of the speed at which charge carriers pass through a material under the influence of an electric field, the carriers being holes (or positive charge units) in the case of a p-type semiconductor material and electrons (or negative charge units) in the case of an n-type semiconductor material. This parameter depends on the device structure and can be measured using field effect devices or space charge limited current measurement.

As used herein, a compound may be considered "environmentally stable" or "stable under ambient conditions" for a transistor using the compound as its semiconductor material when the carrier mobility exhibited by the transistor substantially maintains its initial measurement after the compound is exposed to ambient conditions (including air, ambient temperature and humidity) for a period of time. For example, a transistor using the compound may be described as stable if it exhibits a carrier mobility that differs from its initial value by no more than 20% or no more than 10% after exposure to ambient conditions (including air, humidity and temperature) for a period of more than 3 days, 5 days or 10 days.

As used herein, the Fill Factor (FF) is the ratio of the actual maximum available power (Pm or Vmp Jmp) given in percentage to the theoretical (not actually available) power (Jsc Voc). Therefore, FF can be determined using the following equation:

FF＝(Vmp*Jmp)/(Jsc*Voc)

where Jmp and Vmp represent the current density and voltage, respectively, at the maximum power point (Pm) obtained by varying the resistance in the circuit until J × Vis is at its maximum; jsc and Voc denote short-circuit current and open-circuit voltage, respectively. Fill factor is a key parameter for evaluating the performance of solar cells. Commercial solar cells typically have a fill factor of about 60% or higher.

As used herein, the open circuit voltage (Voc) is the potential difference between the anode and cathode of the device when no external load is connected.

As used herein, the Photoelectric Conversion Efficiency (PCE) of a solar cell is the percentage of power converted from absorbed light to electrical energy. The PCE of a solar cell can be calculated by dividing the maximum power point (Pm) under Standard Test Conditions (STC) by the input light irradiance (E in W/m2) and the surface area of the solar cell (Ac in m 2). STC generally refers to a temperature of 25 ℃ and irradiance of 1000W/m2, spectrum of air mass 1.5(AM 1.5).

As used herein, a component (e.g., a thin film layer) is considered "photoactive" if it contains one or more compounds that can absorb photons to produce excitons that are used to generate a photocurrent.

As used herein, "solution processable" refers to a compound, material, or composition that can be used in a variety of liquid phase processes including spin coating, printing (e.g., inkjet printing, gravure printing, offset printing, and the like), spray coating, electrospray coating, drop coating, dip coating, blade coating, and the like.

As used herein, "semi-crystalline polymer" refers to a polymer that has an inherent tendency to at least partially crystallize upon cooling from the molten state or upon precipitation from solution when subjected to dynamically favorable conditions such as slow cooling or slow solvent evaporation, and the like. Whether crystalline or not can be readily identified by using several analytical methods, such as Differential Scanning Calorimetry (DSC) and/or X-ray diffraction (XRD).

As used herein, "annealing" refers to a post-deposition heat treatment of a semi-crystalline polymer film in air or under reduced/increased pressure for a duration of more than 100 seconds, and "annealing temperature" refers to the highest temperature of the polymer film during an annealing process of at least 60 seconds. Without being bound to any particular theory, it is believed that annealing may increase the crystallinity of the polymer film, thereby increasing the field effect mobility. The increase in crystallinity can be monitored by several methods, such as comparing the Differential Scanning Calorimetry (DSC) or X-ray diffraction (XRD) measurements of the polymer film as precipitated and the polymer film after annealing.

As used herein, "polymeric compound" (or "polymer") refers to a molecule containing one or more repeating units joined by covalent chemical bonds. The polymeric compound may be represented by formula I:

*-(-(Ma)_x—(Mb)_y—)_z*

general formula I

Wherein Ma and Mb are each a repeating unit or a monomer. The polymer may have only one type of repeating unit, or may contain two or more different repeating units. When the polymer compound has only one type of repeating unit, it may be referred to as a homopolymer. When the high molecular compound has two or more different repeating units, the term "copolymer" or "copolymerized compound" may be used. For example, the co-polymer compound may comprise repeat units wherein Ma and Mb represent two different repeat units. Unless otherwise specified, the assembly of the repeat units in the copolymer can be head-to-tail, head-to-head, or tail-to-tail. Further, unless otherwise specified, the copolymer may be a random copolymer, an alternating copolymer, or a block copolymer. For example, formula I can be used to represent a copolymer having a mole fraction of x Ma and a mole fraction of y Mb in the copolymer, where the comonomers Ma and Mb repeat in an alternating, random, regiorandom, regioregular, or block fashion, with the number of repeats being z. In addition to its composition, the polymer compound can be characterized by the degree of polymerization (n) and the molar mass (e.g., number average molecular weight (M) and/or weight average molecular weight (Mw), depending on the measurement technique).

As used herein, "halo" or "halogen" refers to fluoro, chloro, bromo, and iodo.

As used herein, "alkyl" refers to a straight or branched chain saturated hydrocarbon group. Examples of alkyl groups include methyl (Me), ethyl (Et), propyl (e.g., n-propyl and z ' -propyl), butyl (e.g., n-butyl, z ' -butyl, sec-butyl, tert-butyl), pentyl (n-pentyl, z ' -pentyl, -pentyl), hexyl, and the like. In various embodiments, the alkyl group can have 1 to 40 carbon atoms (i.e., C1-40 alkyl), for example, 1 to 30 carbon atoms (i.e., C1-30 alkyl). In some embodiments, alkyl groups may have 1 to 6 carbon atoms, and may be referred to as "lower alkyl". Examples of lower alkyl groups include methyl, ethyl, propyl (e.g., n-propyl and z '-propyl), and butyl (e.g., n-butyl, z' -butyl, sec-butyl, tert-butyl). In some embodiments, alkyl groups may be substituted as described herein. Alkyl groups are typically unsubstituted by other alkyl, alkenyl or alkynyl groups.

As used herein, "alkenyl" refers to a straight or branched chain alkyl group having one or more carbon-carbon double bonds. Examples of alkenyl groups include ethenyl, propenyl, butenyl, pentenyl, hexenyl, butadienyl, pentadienyl, hexadienyl, and the like. The one or more carbon-carbon double bonds may be in the chain (e.g., 2-butene) or at the terminus (e.g., 1-butene). In various embodiments, alkenyl groups can have 2 to 40 carbon atoms (i.e., C2-40 alkenyl groups), for example, 2 to 20 carbon atoms (i.e., C2-20 alkenyl groups). In some embodiments, the alkenyl group may be substituted as described herein. Alkenyl groups are typically unsubstituted by other alkenyl, alkyl, or alkynyl groups.

As used herein, "fused ring" or "fused ring moiety" refers to a polycyclic ring system having at least two rings, wherein at least one ring is aromatic and the aromatic ring (carbocyclic or heterocyclic) shares the same chemical bond with at least one other ring (the rings are aromatic or non-aromatic and are carbocyclic or heterocyclic). These polycyclic ring systems can be highly p-conjugated and can be substituted as described herein.

As used herein, "heteroatom" refers to an atom of any element other than carbon or hydrogen, including, for example, nitrogen, oxygen, silicon, sulfur, phosphorus, and selenium.

As used herein, "aryl" refers to an aromatic monocyclic ring system, or a polycyclic ring system, wherein in the polycyclic ring system two or more aromatic hydrocarbon rings are fused (i.e., have a common chemical bond) together, or at least one aromatic monocyclic hydrocarbon ring is fused to one or more cycloalkyl and/or cycloheteroalkyl rings. The aryl group can have 6 to 24 carbon atoms in its ring system (e.g., a C6-24 aryl group), which can include multiple fused rings. In some embodiments, the polycyclic aryl group can have 8 to 24 carbon atoms. The aromatic ring may be covalently linked to the particular chemical structure at any suitable ring position thereof. Examples of the aryl group having only an aromatic carbocyclic ring include phenyl, 1-naphthyl (bicyclic), 2-naphthyl (bicyclic), anthracenyl (tricyclic), phenanthrenyl (tricyclic), pentacenyl (pentacyclic), and the like. Examples of polycyclic ring systems in which at least one aromatic carbocyclic ring is fused to one or more cycloalkyl and/or cycloheteroalkyl rings include benzo derivatives of cyclopentane (i.e., indanyl, which is a 5, 6-bicyclic cycloalkyl/aryl ring system), cyclohexane (i.e., tetrahydronaphthyl, which is a 6, 6-bicyclic cycloalkyl/aryl ring system), imidazoline (i.e., benzimidazolinyl, which is a 5, 6-bicyclic cycloheteroalkyl/aryl ring system), and pyran (i.e., chromenyl, which is a 6, 6-bicyclic cycloheteroalkyl/aryl ring system). Other examples of aryl groups include benzodioxanyl (benzodioxanyl), benzodioxolyl (benzodioxolyl), chromanyl, indolinyl, and the like. In some embodiments, aryl groups may be substituted as described herein. In some embodiments, an aryl group may have one or more halogen substituents, and may be referred to as a "haloaryl". Perhaloaryl, that is, aryl in which all hydrogen atoms are replaced with halogen atoms (e.g., -C6F5), is included within the definition of "haloaryl". In certain embodiments, an aryl group is substituted with another aryl group, and may be referred to as a biaryl group. Each aryl group in the biaryl group may be substituted as described herein.

As used herein, "heteroaryl" refers to an aromatic monocyclic ring system containing at least one heteroatom selected from oxygen, nitrogen (N), sulfur (S), silicon (Si), and selenium (Se) in the ring, or a polycyclic ring system in which at least one ring in the ring system is aromatic and at least one heteroatom is contained in the ring. The polycyclic heteroaryl group may include polycyclic heteroaryl groups having two or more heteroaryl rings fused together, as well as polycyclic heteroaryl groups having at least one monocyclic heteroaryl ring fused to one or more aromatic carbocyclic rings, non-aromatic carbocyclic rings, and/or non-aromatic cycloheteroalkyl rings. The heteroaryl group as a whole may have 5 to 24 ring atoms and contain 1-5 ring heteroatoms (i.e., a 5-20 membered heteroaryl group). Heteroaryl groups may be attached to a defined chemical structure at any heteroatom or carbon atom, provided that structural stability is ensured. Typically, the heteroaryl ring does not contain an O-O, S-S or S-O bond. However, one or more of the N or S atoms in the heteroaryl group can be oxidized (e.g., pyridine oxide thiophene S-oxide, thiophene S, S-dioxide). Examples of heteroaryl groups include, for example: a 5-or 6-membered monocyclic and 5-6 bicyclic ring system as shown below: where T is O, S, NH, N-alkyl, N-aryl, N- (aralkyl) (e.g., N-benzyl), SiH2, SiH (alkyl), Si (alkyl) 2, SiH (arylalkyl), Si (arylalkyl) 2, or Si (alkyl) (arylalkyl). Examples of such heteroaromatic rings include pyrrolyl, furyl, thienyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazolyl, tetrazolyl, pyrazolyl, imidazolyl, isothiazolyl, thiazolyl, thiadiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, indolyl, isoindolyl, benzofuranyl, benzothienyl, quinolyl, 2-methylquinolyl, isoquinolyl, quinoxalyl, quinazolinyl, benzotriazolyl, benzimidazolyl, benzothiazolyl, benzisothiazole, benzisoxazolyl, benzoxazolyl, cinnolinyl, 1H-indazolyl, 2H-indazolyl, indolizinyl, isobenzofuranyl (isobenzofuranyl), naphthyridinyl, phthalazinyl, pteridine, purinyl, oxazolopyridyl, thiazolopyridyl, imidazopyridinyl, pirenopyridinyl, thienopyridinyl, pyridopyrimidinyl, pyrazinyl, thiazopyridinyl, 2H-indazolyl, quinoxalyl, quinoxalinyl, quinoxal, Pyridopyrazinyl, pyridopyridazinyl, thienothiazolyl, thienooxazolyl, thienoimidazolyl, and the like. Other examples of heteroaryl groups include 4,5,6, 7-tetrahydroindolyl, tetrahydroquinolinyl, benzothienopyridyl, benzofuropyridinyl, and the like. In some embodiments, heteroaryl groups may be substituted as described herein.

In this patent, one or more of the above objects can be achieved by providing an organic compound of the formula:

in another exemplary embodiment, the inventive subject matter also relates to D-a conjugated polymers comprising one or more repeating units of the formula:

in another exemplary embodiment, the inventive subject matter also relates to D-a conjugated polymers having at least one or more repeat units comprising the following structural units:

wherein Ar is as defined herein.

Surprisingly, the peaks of the absorption spectra of polymers comprising such structural units show a significant red shift when the polymer solution is cooled from high temperature (e.g. 140 ℃) to room temperature (>100 nanometers). Surprisingly and advantageously, polymers exhibiting such absorption properties more readily form ideal polymer/fullerene morphologies with many different fullerenes, as evidenced by AFM images of a variety of different polymer/fullerene films (fig. 3). Due to the excellent polymer/fullerene morphology based on such polymers, PC is used₇₁Many fullerenes other than BM can also achieve high efficiency (9%) OPV devices.

The polymer solution is generally prepared in a solvent such as dichlorobenzene at a concentration of 0.1 mg/ml. Upon heating to 140 ℃, the polymers of the present teachings have a UV-Vis absorption peak at 550 nm. Cooling the polymer solution to room temperature resulted in a significant shift in peak absorption to about 740 nm.

In one embodiment in this aspect, the D-a conjugated polymer may comprise one or more repeating units of the formula:

wherein each R is independently selected from the group consisting of linear, branched and cyclic alkyl groups having 2 to 40C atoms, wherein one or more non-adjacent C atoms are optionally substituted by-O-, -S-, -C (O) -O-, -O-C (O) -O-, -CR-⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may optionally be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is⁰And R⁰⁰Independently a linear, branched or cyclic alkyl group. In a preferred embodiment, the Ar group comprises two or more aromatic rings.

In another embodiment, the average molecular weight of the D-A conjugated polymer is in the range of 20,000 to 40,000 g/mole

In another embodiment, the solution of the D-A conjugated polymer exhibits a red shift in the optical absorption spectrum peak of at least 100 nanometers when the conjugated polymer solution is cooled from 140 ℃ to room temperature.

In another exemplary embodiment, the solution of the D-A conjugated polymer exhibits a red shift in the optical absorption spectrum peak at about 740 nanometers when the conjugated polymer solution is cooled from 140 ℃ to room temperature.

In another exemplary embodiment, the D-A conjugated polymer is further characterized as having an optical bandgap of 1.65eV or less.

In some embodiments, the formulation is further characterized in that the D-a conjugated polymer comprises one or more repeating units selected from the group consisting of:

in the D-A conjugated polymer, PBTff4T-OD, PffT2-FTAZ, PID-ffT4 and N2200-2F as acceptors exhibited photoelectric conversion efficiencies between 6.7% and 10.4%. And the D-A conjugated polymers PBT4T-OD, PT2-FTAZ, PID-T4, PDPP-T4 and N2200 show the photoelectric conversion efficiency between 2.6% and 5.3% as acceptors. N2200-2F and N2200 each have a length of 0.3cm²Vs and 0.5cm²Electron hole mobility of/Vs.

In another embodiment, the present patent provides a formulation comprising an organic solvent, a fullerene, and a D-a conjugated polymer:

wherein each R is independently selected from the group consisting of linear, branched, and cyclic alkyl groups having 2 to 40C atoms, wherein one or moreNon-adjacent C atoms may optionally be replaced by-O-, -S-, -C (O) -, -O-, -O-C (O) -O-, -CR⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may optionally be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is⁰And R⁰⁰Independently a linear, branched or cyclic alkyl group.

In another embodiment, fullerenes useful herein may be selected from the group consisting of:

wherein n is 1, 2,4, 5 or 6;

each Ar is independently selected from the group consisting of monocyclic, bicyclic and polycyclic arylene groups, and monocyclic, bicyclic and polycyclic heteroarylene groups, wherein each Ar may contain from 1 to 5 of said arylene or heteroarylene groups, which may be fused or linked together;

each R^xIndependently selected from the group consisting of Ar, linear, branched and cyclic alkyl having 2 to 40C atoms, wherein one or more non-adjacent C atoms may optionally be replaced by-O-, -S-, -C (O) -O-, -O-C (O) -O-, -CR⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may optionally be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is⁰And R⁰⁰Independently is a linear, branched or cyclic alkyl group;

each R1 is independently selected from the group consisting of 2-40Straight, branched and cyclic alkyl of C atoms, wherein one or more non-adjacent C atoms may optionally be replaced by-O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -O-, -CR⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may optionally be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is¹Has a carbon number of more than 1, wherein R⁰And R⁰⁰Independently is a linear, branched or cyclic alkyl group;

each Ar¹Independently selected from the group consisting of monocyclic, bicyclic and polycyclic heteroaryl, wherein each Ar is¹May contain from 1 to 5 of said heteroaryl groups, all of which may be fused or linked together;

each Ar²Independently selected from aryl groups containing 6 or more atoms other than H;

wherein the fullerene spheres represent fullerenes selected from the group consisting of C60, C70, C84, and other fullerenes.

In one embodiment, the fullerene is substituted with one or more functional groups selected from the group consisting of:

wherein each n is 1-6;

each Ar is independently selected from the group consisting of monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene, or each Ar may contain 1-5 of these monocyclic, bicyclic, and polycyclic arylene, and monocyclic, bicyclic, and polycyclic heteroarylene fused or linked together;

each R^xIndependently selected from the group consisting of Ar, linear, branched and cyclic alkyl having 2-40C atoms, wherein one or more are not in phaseThe adjacent C atom may be substituted by-O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -O-, -CR⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may optionally be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is⁰And R⁰⁰Independently is a linear, branched or cyclic alkyl group;

each R¹Independently selected from the group consisting of linear, branched and cyclic alkyl groups having 2 to 40C atoms, wherein one or more non-adjacent C atoms may optionally be replaced by-O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-, -CR⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may optionally be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is¹In which R is greater than 1⁰And R⁰⁰Independently is a linear, branched or cyclic alkyl group;

each R is independently selected from the group consisting of linear, branched, and cyclic alkyl groups having 2 to 40C atoms, wherein one or more non-adjacent C atoms are optionally substituted by-O-, -S-, -C (O) -O-, -O-C (O) -O-, -CR-⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may optionally be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is⁰And R⁰⁰Independently is a linear, branched or cyclic alkyl group;

each Ar¹Independently selected from the group consisting of monocyclic, bicyclic and polycyclic heteroaryl, wherein each Ar is¹May contain 1 to 5 of said heteroaryl groups, said heteroaryl groups may be fused or linked together;

each Ar²Independently selected from aryl groups containing 6 or more atoms in addition to H; and is

Wherein the fullerene spheres represent a group selected from the group consisting of C60, C70, C84 and other fullerenes.

In some embodiments, the formulation is further characterized by fullerenes selected from the group consisting of:

wherein each R is independently selected from the group consisting of linear, branched, and cyclic alkyl groups having 2 to 40C atoms, wherein one or more non-adjacent C atoms may optionally be replaced by-O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-, -CR⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may optionally be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is⁰And R⁰⁰Independently a linear, branched or cyclic alkyl group.

in some embodiments, the formulation is further characterized by a fullerene selected from the group consisting of:

wherein each n is 1-6;

each m is 1, 2,4, 5 or 6;

each q is 1-6;

each R¹And R²Independently selected from the group consisting of C1-4 straight and branched chain alkyl;

in exemplary embodiments, the Organic Electronic (OE) device comprises a coating or printing ink comprising the above-described formulation. Another exemplary embodiment is further characterized in that: the OE device is an Organic Field Effect Transistor (OFET) device. Another exemplary embodiment is further characterized in that the OE device is an Organic Photovoltaic (OPV) device.

In another embodiment of the present subject matter, a film is provided comprising a D-a conjugated polymer and a fullerene, wherein a solution of the D-a conjugated polymer exhibits a red-shift in absorption spectrum values of at least 100 nanometers when the solution is cooled from 140 ℃ to room temperature, and wherein the D-a conjugated polymer contains one or more repeat units having the formula:

wherein each R is independently selected from the group consisting of linear, branched and cyclic alkyl groups having 2 to 40C atoms, wherein one or more non-adjacent C atoms may optionally be replaced by-O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-, -CR⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is a group which is a substituent selected from the group consisting of aryl, heteroaryl, aryloxy, heteroarylcarbonyl, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl, wherein R is a group which is a substituent selected from the group⁰And R⁰⁰Independently a linear, branched or cyclic alkyl group.

Formulations in the present teachings can exhibit semiconducting behavior, e.g., excellent light absorption/charge separation in photovoltaic devices; the material shows good charge transmission/recombination/luminescence in a light-emitting device; and/or exhibit high carrier mobility and/or good current modulation characteristics in field effect devices. In addition, the formulations of the invention also have advantages in terms of processing, for example solution processability under atmospheric conditions and/or good stability (e.g. air stability). The formulations of the present teachings can be used to prepare p-type (donor or hole transporting), n-type (acceptor or electron transporting), or ambipolar semiconductor materials, which in turn can be used to fabricate various organic or hybrid optoelectronic articles, structures, and devices, including organic photovoltaic devices and organic light emitting transistors.

Examples

Example 1 Synthesis of monomers

Step 1:preparation of 4, 7-bis (4- (2-octyldodecyl) -2-thienyl) -2,1, 3-benzothiadiazole (S3)

3- (2-octyldodecyl) thiophene (5.00g, 13.7mmol) was dissolved in 50mL of THF to obtainThe solution was cooled to-78 ℃ under nitrogen. Lithium diisopropylamide (2M, 8.3mL, 16.6mmol) was slowly added dropwise thereto, and the mixture was stirred at-78 deg.C for 1 hour, then returned to 0 deg.C and stirred for another 1 hour. The mixture was then cooled to-78 ℃ and tri-n-butyltin chloride (6.50g, 20mmol) was added in one portion. The reaction mixture was returned to room temperature and stirred overnight. After this time, aqueous KF solution was added and the organic phase was washed three times with water and then with Na₂SO₄And (5) drying. The solvent was removed by rotary evaporation to give the crude product as a yellow oil which was used without further purification. 2- (tri-n-butylstannyl) -4- (2-octyldodecyl) thiophene (1.96g, 3mmol), 4, 7-dibromo-2, 1, 3-benzothiadiazole (305mg, 1mmol), Pd dissolved in 10mL of THF₂(dba)₃(11mg, 0.02mmol) and P (o-tol)₃(24mg, 0.08mmol) of the mixture was refluxed under nitrogen overnight. The reaction mixture was cooled to room temperature and the solvent was removed by evaporation. The residue was purified by flash column chromatography (eluent: n-hexane) to give the product as a yellow solid (650mg, 73%).

Step 2:process for preparing 4, 7-bis (5-bromo-4- (2-octyldodecyl) -2-thienyl) -2,1, 3-benzothiadiazole (S4) And (4) preparation.

S3(1.22g, 1.36mmol) and silica gel (20mg) were mixed well in 20mL chloroform and N-bromosuccinimide (540mg, 3.00mmol) was added to the mixture at 0 ℃. The reaction mixture was allowed to come to room temperature and stirred overnight. Washed three times with water, and the organic phase was then washed with Na₂SO₄Drying and evaporating to remove the solvent. The residue was purified by flash column chromatography (eluent: n-hexane) to give the product as an orange solid (1.42g, 99%).

And step 3:4, 7-bis (5-bromo-4- (2-octyldodecyl) thiophen-2-yl) -5, 6-difluoro-2-propyl-2H- Benzo [ d ] carbonyl][1,2,3]Preparation of triazole (S7)。

Into a 50mL tube were added S5(197mg, 1mmol), S6(1.33g, 3mmol), Pd (TFA)₂(16.6mg，0.05mmol)、Ag₂O (927mg, 4mmol) and DMSO. Then heated and stirred at 80 ℃ for 8 hours. After cooling to room temperature, the reaction mixture was filtered, diluted with chloroform and washed with brine. The organic layer was washed with Na₂SO₄Dried, filtered and concentrated. The residue was purified by silica gel chromatography to give the pure product (720mg, 63.7% yield).

Example 2 Synthesis of Polymer

ffT2-TBTT can be synthesized by microwave reaction or conventional reaction. In N₂In a protective glove box, monomers S4(96.5mg, 0.095mmol), (3,3 '-difluoro- [2,2' -bithiophene)]-5,5' -diyl) bis (trimethylstannane) (50.2mg, 0.095mmol), Pd₂(dba)₃(1.1mg, 0.002mmol) and P (o-tol)₃To the mixture (2.4mg, 0.008mmol) was added 1.6mL of chlorobenzene. The reaction mixture was then sealed and heated at 145 ℃ for 2 days (or microwave reaction at 160 ℃ for 30 minutes). The mixture was cooled to room temperature, and 10mL of toluene was added, followed by precipitation with methanol. The crude product was collected by filtration and extracted by soxhlet extraction (CH)₂Cl₂，CHCl₃And chlorobenzene) and repeated precipitation to purify. The solvent was removed by rotary evaporation, the residue was dissolved in chlorobenzene and precipitated with methanol. The solid was collected by filtration and dried in vacuo to give polymer as a dark green solid (89mg, 88%). 1H NMR (400MHz, CDCl3) δ 8.04(s,2H),7.90(s,2H),7.08(s,2H),2.89(d, J ═ 6.6Hz,4H),1.91(s,2H), 1.51-1.23 (m,64H),0.92(t, J ═ 6.8Hz, 12H). C₆₂H₈₈F₂N₂S₅Elemental analysis of (2): c, 70.27; h, 8.37; f, 3.59; n, 2.64; and S, 15.13. Experimental values: c, 70.33; h, 8.16; f, 3.70; n, 2.72; s, 14.91. GPC number average molecular weight (M)_n): 25 kDa; weight average molecular weight (M)_w)：37kDa。

T2-TBTT can be synthesized by microwave reaction or conventional reaction. In N₂In the glove box, monomers S4(96.5mg, 0.095mmol) and [2,2'-dithiophene]-5,5' -diyl) bis (trimethylstannane) (46.8mg, 0.095mmol), Pd₂(dba)₃(1.1mg, 0.002mmol) and P (o-tol)₃To the mixture (2.4mg, 0.008mmol) was added 1.6mL of chlorobenzene. The reaction mixture was sealed and heated at 145 ℃ for 2 days (or microwave reaction at 160 ℃ for 30 minutes). The mixture was cooled to room temperature, and 10mL of toluene was added, followed by precipitation with methanol. The solid was collected by filtration and extracted by soxhlet extraction (CH)₂Cl₂，CHCl₃And chlorobenzene) and repeated precipitation purification. The solvent was removed by rotary evaporation and the residue was dissolved in chlorobenzene and precipitated with methanol. The solid was collected by filtration and dried in vacuo to give polymer as a dark green solid (81mg, 80%).¹H NMR(400MHz,CDCl₃) δ 8.05(s,2H),7.89(s,2H),7.25(d, J ═ 3.8Hz,2H),7.22(d, J ═ 3.7Hz,2H)2.90(d, J ═ 6.9Hz,4H),1.92(s,2H), 1.51-1.25 (m,64H),0.92(t, J ═ 6.6Hz, 12H). GPC number average molecular weight (M)_n): 18 kDa; weight average molecular weight (M)_w)：30kDa。

ffT2-TTrzT can be synthesized by microwave reaction or conventional reaction. In N₂In a protective glove box, monomers S7(107.4mg, 0.095mmol) and [2,2' -bithiophene were added]-5,5' -diyl) bis (trimethylstannane) (46.8mg, 0.095mmol), Pd₂(dba)₃(1.1mg, 0.002mmol) and P (o-tol)₃To the mixture (2.4mg, 0.008mmol) was added 1.6mL of chlorobenzene. The reaction mixture was sealed and heated at 145 ℃ for 2 days (or microwave reaction at 160 ℃ for 30 minutes). The mixture was cooled to room temperature, and 10mL of toluene was added, followed by precipitation with methanol. The solid was collected by filtration and extracted by soxhlet extraction (CH)₂Cl₂，CHCl₃And chlorobenzene) and repeated precipitation purification. The solvent was removed by rotary evaporation and the residue was dissolved in chlorobenzene and precipitated with methanol. The solid was collected by filtration and dried in vacuo to give the polymer as a dark green solid (75mg, 70%).¹H NMR(400MHz,CDCl₃)δ8.18(s,2H),7.09(s,2H),4.83(s,2H),2.91(d,J＝7.3Hz,4H),2.31(dd,J＝14.5,7.2Hz,2H),1.91(s,2H),1.52–1.27(m,64H),1.17(t,J＝7.4Hz,3H),0.92(dd,J＝6.9,5.4Hz,12H)。C₆₅H₉₃F₄N₃S₄Elemental analysis of (2): c, 69.66; h, 8.36;and N, 3.75. Experimental values: c, 69.29; h, 8.28; and N, 3.90. Mn: 41.5kDa, Mw: 76.5 KDa; PDI is 1.84.

T2-TTrzT can be synthesized by microwave reaction or conventional reaction. To monomers S4(107.4mg, 0.095mmol), [2,2' -bithiophene]-5,5' -diyl) bis (trimethylstannane) (46.8mg, 0.095mmol), Pd₂(dba)₃(1.1mg, 0.002mmol) and P (o-tol)₃To the mixture (2.4mg, 0.008mmol) was added 1.6mL of chlorobenzene. The reaction mixture was sealed and heated at 145 ℃ for 2 days (or microwave reaction at 160 ℃ for 30 minutes). The mixture was cooled to room temperature, and 10mL of toluene was added, followed by precipitation with methanol. The solid was collected by filtration and extracted by soxhlet extraction (CH)₂Cl₂，CHCl₃And chlorobenzene) and repeated precipitation purification. The solvent was removed by rotary evaporation and the residue was dissolved in chlorobenzene and precipitated with methanol. The solid was collected by filtration and dried in vacuo to give the polymer as a dark green solid (75mg, 72%).¹H NMR(400MHz,CDCl₃)δ8.19(s,2H),7.26(d,J＝3.7Hz,2H),7.23(d,J＝3.8Hz,2H),4.83(s,2H),2.92(d,J＝6.5Hz,4H),2.31(dd,J＝14.5,7.2Hz,2H),1.92(s,2H),1.55–1.26(m,64H),1.18(t,J＝7.4Hz,3H),0.92(dt,J＝7.0,3.4Hz,12H)。C₆₅H₉₅F₂N₃S₄Elemental analysis of (2): c, 71.97; h, 8.83; and N, 3.87. Experimental values: c, 70.58; h, 8.24; and N, 4.48. Mn: 80.9 KDa; mw: 150.8 KDa; PDI is 1.86.

Example 3 characterization of the Polymer

Example 3 a:optical Properties

The optical absorption measurements of the polymers in example 2 were performed in DCB solution of the polymers using a Cary UV-vis spectrometer. The band gap of the polymer was calculated by measuring the position of the onset of absorption. The optical absorption spectrum is shown in FIG. 1.

Example 3 b:electric properties

Cyclic voltammetry was performed in 0.1M electrolyte solution of tetrabutylammonium hexafluorophosphate with platinum electrode as working and counter electrode. Taking an Ag/AgCl electrode as a reference electrode; the Fc/Fc + redox couple was used as an external standard (as shown in FIGS. 2 a-d).

Example 4-Preparation of devices

Example 4 a:preparation and measurement of photovoltaic cells

Using a sheet resistance of

Pre-patterned (pre-patterned) ITO coated glass at 15 Ω/square was used as the substrate. The substrate was continuously sonicated in sequence in soap deionized water, acetone, and isopropanol. After treatment under UV/ozone atmosphere for 60 minutes, ZnO precursor solution (diethyl zinc) was spin-coated onto the substrate at 5000rpm to prepare a ZnO electron transport layer. Solutions of the active layer were prepared in CB/DCB or CB/DCB/DIO at different ratios (polymer concentration: 7-12 mg/mL). The active layer solution should be stirred on a hot plate at 100-120 ℃ for at least 3 hours to ensure complete dissolution of the polymer. Then at N₂The thickness of the coating is spun from the warm solution in a glove box at the rotating speed of 600-

250-350 nm. The polymer/fullerene film was then annealed at 80 ℃ for 5 minutes and then transferred to the vacuum chamber of a thermal evaporator inside the same glove box. At 3X 10^-6In a degree of vacuum of Torr, MoO was deposited₃Or V₂O₅As an anode interlayer followed by 100 nm of Al as a top electrode. All cells were sealed with epoxy in a glove box. Using a Newport solar simulator at AM1.5G (100 mW/cm)²) The J-V characteristics of the devices were measured. The light intensity was calibrated using a standard Si diode (with KG5 filter, available from PV measurement) to ensure that the spectral intensity met the standard. The J-V characteristics were then recorded using a Keithley 236 source measurement unit. The device area of a typical cell is about 5.9mm²A metal mask with an aperture that is consistent with the device area is used to define the device area. Characterization of the EQE used a Newport EQE system equipped with a standard Si diode. Monochromatic light is produced by a Newport 300W light source. The Voc, Jsc, FF and PCE of OPV devices in the present teachings are summarized in the following table.

TABLE 1, ffT2-TBTT and T2-TBTT with PC₇₁PSC performance of BM preparation

Example 5

(E) -6,6 ' -bis (5-bromo-4- (2-octyldodecyl) thiophen-2-yl) -1,1 ' -dioctyl- [3, 3' -bi-octyl-) Indolfull fork]Preparation of (E) -2, 2' -dione (S11)

Mixing S8(258mg, 0.4mmol) and Pd₂(dba)₃(7mg, 0.008mmol) and P (o-tol)₃(10mg, 0.03mmol) was dissolved in 20mL of toluene to prepare a solution, to which S9(654mg, 1.0mmol) was added under N2, and the reaction was refluxed overnight. After the reaction mixture was cooled to room temperature, an aqueous solution of KF was added, and the organic phase was washed three times with water, then with Na₂SO₄And (5) drying. The solvent was removed by evaporation and the residue was purified by flash column chromatography (eluent: n-hexane/DCM ═ 3: 1) to give S10(368mg, 76%) as a black solid.

S10(243mg, 0.2mmol) was dissolved in 10mL CHCl₃To prepare a solution, NBS (71mg, 0.4mmol) was added to the solution at 0 deg.C, the reaction was stirred overnight, and then the mixture was washed three times with water, then Na was used₂SO₄And (5) drying. The solvent was removed by evaporation and the residue was purified by flash column chromatography (eluent: n-hexane/DCM ═ 3: 1) to give S11(250mg, 80%) as a dark solid.

With respect to the polymer PID-ffT 4: to a 10mL reaction tube were added monomer S11(27.4mg, 0.02mmol), monomer 8(10.6mg, 0.02mmol), tris (dibenzylideneacetone) dipalladium (0.5mg), tri-o-tolylphosphine (1.0mg), and CB (0.3mL), and the cap was sealed under nitrogen. The reaction was stirred vigorously at 140 ℃ for 24 hours. After cooling to room temperature, the reaction mixture was poured into 100mL of methanol. The precipitate was collected and further purified by soxhlet extraction with methanol, acetone, chloroform, chlorobenzene in that order. The polymer was recovered as a solid from the chlorobenzene fraction to give the product as a dark green solid (38mg, 70%). The polymer PID-ffT4 can be used to prepare polymer solar cells with 7% efficiency, which is significantly higher than that of homologous polymers without any fluorination.

With respect to the polymer PDPPT2-ffT 2: to a 10mL tube were added monomer S12(22.6mg, 0.02mmol), monomer 8(10.6mg, 0.02mmol), tris (dibenzylideneacetone) dipalladium (1.0mg), tri-o-tolylphosphine (2.0mg), and CB (0.3mL), and the tube was sealed under a nitrogen blanket. The reaction was stirred vigorously at 140 ℃ for 24 hours. After cooling to room temperature, the reaction mixture was poured into 100mL of methanol. The precipitate was collected and further purified by soxhlet extraction with methanol, acetone, chloroform in that order. The polymer was recovered as a solid from the chlorobenzene fraction to give the product as a dark green solid (15mg, 65%).

It will be apparent to those skilled in the art to which the subject matter pertains that individual differences from the precise teachings of this patent will be apparent to those skilled in the art to which the subject matter pertains without departing from the spirit and scope of the following claims. This patent covers no limitations to the operation, properties, or components of the embodiments as defined in the description, since the preferred embodiments and other descriptions are presented only for illustrating certain aspects of the invention. Indeed, various obvious modifications of the described modes for carrying out the invention, which are obvious to those skilled in chemistry and biochemistry or related fields, are intended to be within the scope of the following claims.

Claims

1. An electron-donating-electron-accepting conjugated polymer comprising one or more repeat units having the formula:

wherein Ar is an aromatic group selected from the group consisting of:

wherein each R is independently selected from the group consisting of linear, branched and cyclic alkyl groups having 2 to 40C atoms, wherein one or more non-adjacent C atoms are optionally substituted by-O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-, -CR⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is a group represented by formula (I) or (ii) wherein R is a group represented by formula (ii) or (iii⁰And R⁰⁰Independently a linear, branched or cyclic alkyl group.

2. The electron donating-electron accepting conjugated polymer of claim 1 wherein the average molecular weight of the electron donating-electron accepting conjugated polymer is between 20,000 g/mole and 40,000 g/mole.

3. The electron-donating-electron-accepting conjugated polymer of claim 1, wherein the peak of the optical absorption spectrum of the solution of the electron-donating-electron-accepting conjugated polymer exhibits a red shift of at least 100 nm when the solution of the electron-donating-electron-accepting conjugated polymer is cooled from 140 ℃ to room temperature.

4. The electron donating-electron accepting conjugated polymer of claim 1, wherein the peak of the optical absorption spectrum of the solution of the electron donating-electron accepting conjugated polymer exhibits a red shift at about 740 nm when the solution of the electron donating-electron accepting conjugated polymer is cooled from 140 ℃ to room temperature.

5. The electron-donating-electron-accepting conjugated polymer of claim 1, further characterized by: the electron-donating-electron-accepting conjugated polymer has an optical band gap of 1.65eV or less.

6. The electron donating-electron accepting conjugated polymer of claim 1 wherein the electron donating-electron accepting conjugated polymer is selected from the group consisting of:

7. the electron-donating-electron-accepting conjugated polymer of claim 6, wherein the photoelectric conversion efficiency of PBT4ffT-OD, PffT2-FTAZ, PID-ffT4, and N2200-2F as acceptors is between 6.7% and 10.4%.

8. The electron-donating electron-accepting conjugated polymer according to claim 6, wherein the electron-hole mobility of N2200-2F is 0.3cm²/Vs。

9. A formulation comprising an organic solvent, a fullerene and an electron donating-electron accepting conjugated polymer according to any one of claims 1-8

10. The formulation of claim 9, wherein the fullerene is selected from the group consisting of:

wherein

Each n is 1, 2,4, 5 or 6;

each R¹Independently selected from the group consisting of linear, branched and cyclic alkyl groups having 2 to 40C atoms, wherein one or more non-adjacent C atoms may optionally be replaced by-O-, -S-, -C (O) -, -C (O-) -O-, -O-C (O) -, -O-, -CR⁰＝CR⁰⁰-or-C ≡ C-substitution and wherein one or more H atoms may optionally be replaced by F, Cl, Br, I or CN, or represents aryl, heteroaryl, aryloxy, heteroaryloxy, arylcarbonyl, heteroarylcarbonyl, arylcarbonyloxy, heteroarylcarbonyloxy, aryloxycarbonyl or heteroaryloxycarbonyl having 4 to 30 ring atoms unsubstituted or substituted by one or more non-aromatic groups, wherein R is¹Has a carbon number of more than 1, wherein R⁰And R⁰⁰Independently is a linear, branched or cyclic alkyl group;

each Ar¹Independently selected from the group consisting of a monocyclic ring,Bicyclic and polycyclic heteroaryl, wherein each Ar¹May contain from 1 to 5 of said heteroaryl groups, all of which may be fused or linked together;

wherein the fullerene balls represent fullerenes selected from the group consisting of C60, C70, or C84 fullerenes.

11. An Organic Electronic (OE) device comprising a coating or printing ink comprising a formulation according to claim 9.

12. The OE device of claim 11, wherein: the OE device is an Organic Field Effect Transistor (OFET) device.

13. The OE device of claim 11, wherein: the OE device is an Organic Photovoltaic (OPV) device.

14. A thin film comprising the electron-donating-electron-accepting conjugated polymer according to any one of claims 1 to 8 and a fullerene.

15. The film of claim 14, wherein the fullerene is as defined in claim 10.